PURPOSE: To reduce contact resistance with the contact terminal on the device side by applying a chemical treatment using hydrochloric acid or the like on the surface of stainless steel of an outer terminal element.
CONSTITUTION: The positive electrode mixture 2 of manganese dioxide or the like, the separator layer 5, and the negative electrode 4 of amalgamated zinc or the like, are provided between the case 1a serving as the positive terminal 1 and the sealing plate 3a serving as the negative terminal 3. These are enclosed by the sealing plate 3a fitted with the annular gasket of an L-shaped section to form a button type cell. The outside terminal portion made of stainless steel in the terminals 1 and 3 of the cell is treated by dipping in a hydrochloric acid solution or a mixture of hydrochloric acid and a non-oxidative acid, e.g., sulfuric acid, etc., washed with water, and then dried. In this case, the preferred temperature of the acid solution is ordinary temperature to 60°C, and washing with water and drying are preferably conducted at a temperature below 90°C. Also, the preferred concentration of the hydrochloric acid solution is 10∼25wt% (as hydrogen chloride).
ITOU ZENICHIROU
MITAMURA TOMOKAZU
OKAZAKI RIYOUJI
